Showing papers on "Molecular solid published in 1970"
01 Nov 1970
TL;DR: In this article, the critical surface tension for polycrystalline ice surface is found to be about 29 dynes/cm or above 40 dynes /cm. But the linear temperature dependence does not permit the locating of any point down to −50°C at which change to a rigid surface structure would appear to occur.
Abstract: Advancing contact angles on flat, polycrystalline ice are reported for a number of liquids at −5°C Depending on which series of liquids is utilized, the critical surface tension for ice surface may be found to be about 29 dynes/cm or above 40 dynes/cm Advancing angles for carbon disulfide on the basal plane of single-crystal ice are also given for the temperature range −5°C to −50°C and show a constant temperature coefficient of 035°/°C The contact angle at −5°C, 42°, suggests that the ice surface is liquid like, but the linear temperature dependence does not permit the locating of any point down to −50°C at which change to a rigid surface structure would appear to occur These two sets of apparently dichotomous behavior as well as that of ice as an adsorbent for vapors are explained in terms of whether or not a given liquid or adsorbed vapor restructures the ice surface in the temperature range where the latter is mobile Class A liquids, which include carbon disulfide and halobenzenes, are inert with respect to such action, whereas class B liquids, which include alkanes and chloroalkanes, are surface restructuring The distinguishing features of class A and B liquids are discussed briefly
24 citations
TL;DR: In this article, the EPR spectrum of O2 impurity in solid N2 has been observed at K band and at X band and the results are consistent with specific heat results for this system and indicate that the 3Σ state is split in zero field by 105 ǫ± 15 GHz, and a small temperaturedependent splitting of the upper doublet is indicated by the results, and the possibility of using O2 as a probe to investigate the motions of molecular solids is pointed out.
Abstract: The EPR spectrum of O2 impurity in solid N2 has been observed at K band and at X band. The results are consistent with the specific‐heat results for this system and indicate that the 3Σ state is split in zero field by 105 ± 15 GHz. A small temperature‐dependent splitting of the upper doublet is indicated by the results, and the possibility of using O2 as a probe to investigate the motions of molecular solids is pointed out.
13 citations
TL;DR: In this paper, the results of the study of the Costa Ribeiro Effect (charge storage during phase changes), photo and themeelectrets (charge and polarization storage due to dipoles, spacecharge or electronic effects associated with trapping) and ferroelectricity (in this case only related to ice) were presented.
Abstract: Charge and polarization storage in solids has now been studied for a great number of phenomena and a large number of materials. In the present work we describe mainly the results of our group, at S. Carlos, Brazil, in the study of the Costa Ribeiro Effect (charge storage during phase changes), photo and themeelectrets (charge and polarization storage due to dipoles, spacecharge or electronic effects associated with trapping) and ferroelectricity (in this case only related to ice). As for materials we have investigated the above effects with molecular solids (naphtalene and sulphur), ionic solids (metal doped KCl and NaCl, Ce doped CaF and fluoroapathite) and ice (for which we describe its behavior for the Costa Ribeiro Effect, the thermoelectret and its ferroelectric behavior).
10 citations
1 citations
1 citations